Move some API rules out of top-level Android.bp

These defaults are used by api / stub modules, so move them into
the api subdir.

Test: m
Merged-In: I97661daa1c4c3cba6c31ccf1212334a41adaa271
Change-Id: I97661daa1c4c3cba6c31ccf1212334a41adaa271
2 files changed